Luminescent Au(III)–M(I) (M = Cu, Ag) Aggregates Based on Dicyclometalated Bis(alkynyl) Gold Anions

The syntheses and structures of a series of complexes based on the C∧C-chelated Au(III) unit (C∧C = 4,4′-bis(t-butyl) 2,2′-biphenyl-1,1′-diyl) are reported, namely, [{(C∧C)Au(C≡CtBu)2}2M2], (C∧C)Au(C≡CR)(C≡NXyl), and [{(C∧C)Au(C≡CR)2}{M(C≡NXyl)}] (M = Ag, Cu; R = tBu, C6H4tBu-4, C6H4OMe-4; Xyl = 3,5-Me2C6H3). The X-ray structures reveal a broad range of dispositions determined by the different coordination modes of Ag(I) or Cu(I). The complexes are bright photoemitters in the solid state and in poly(methyl methacrylate) (PMMA) films. The photoluminescence is dominated by 3IL(C∧C) transitions, with indirect effects from the rest of the molecules, as supported by theoretical calculations. This work opens up the possibility of accessing Au(III) carbon-rich anions to construct photoluminescent aggregates.


S14
for the minor components of the disordered t Bu group) were refined with anisotropic thermal parameters. The hydrogen atoms were included in idealised positions and their Uiso values were set to ride on the Ueq values of the parent carbon atoms. At the conclusion of the refinement, wR 2 = 0.043 and R 1 = 0.024 (2B) for all 6867 reflections weighted w = [σ 2 (F o 2 ) + (0.0160 P) 2 + 1.6783 P] -1 with P = (F o 2 + 2F c 2 )/3; for the 'observed' data only, R 1 = 0.020.
In the final difference map, the highest peak (ca 0.87 eÅ -3 ) was near the Au centre.
Scattering factors for neutral atoms were taken from reference (S5). Computer programs used in this analysis have been noted above, and were run through WinGX (S4) on a Dell Optiplex 780 PC at the University of East Anglia.

Crystal structure analysis of [{(C^C)Au(C≡C t Bu) 2 } 2 Cu 2 ] 2
Crystal data: C 32 H 42 AuCu, M = 687.16. Monoclinic, space group P2 1 /n (equiv. to no. 14), a The crystal was a colourless block. From a sample under oil, one, ca 0.10 x 0.10 x 0.15 mm, was mounted on a small loop and fixed in the cold nitrogen stream on a Rigaku Oxford Diffraction XtaLAB AFC12 (RCD3) diffractometer, equipped with Mo-Kα radiation, CCD plate detector and mirror monochromator. Intensity data were measured by thin-slice ω-scans.
Total no. of reflections recorded, to θ max = 27.5, was 114,568 of which 6772 were unique (Rint = 0.049 ); 6507 were 'observed' with I > 2σ I . Data were processed using the CrysAlisPro-CCD and -RED (S1) programs. The structure was determined by the intrinsic phasing routines in the SHELXT program (S2) and refined by fullmatrix least-squares methods, on F 2 's, in SHELXL (S2). The non-hydrogen atoms were refined with anisotropic thermal parameters. The hydrogen atoms were included in idealised positions and their Uiso values were set to ride on the Ueq values of the parent carbon atoms. At the conclusion of the refinement, wR 2 = 0.047 and R 1 = 0.023 (2B) for all 6772 reflections weighted w = [σ 2 (F o 2 ) + (0.0029 P) 2 + 10.0221 P] -1 with P = (F o 2 + 2F c 2 )/3; for the 'observed' data only, R 1 = 0.021.
In the final difference map, the highest peak (ca 1.3 eÅ -3 ) was near H(25b).

S15
Scattering factors for neutral atoms were taken from reference (S5). Computer programs used in this analysis have been noted above, and were run through WinGX (S4) on a Dell Optiplex 780 PC at the University of East Anglia.
The crystal was a colourless plate. From a sample under oil, one, ca 0.20 x 0.15 x 0.05 mm, was mounted on a small loop and fixed in the cold nitrogen stream on a Rigaku Oxford Diffraction XtaLAB Synergy diffractometer, equipped with Mo-Kα radiation, HyPix detector and mirror monochromator. Intensity data were measured by thin-slice ω-scans. Total no. of reflections recorded, to θ max = 27.5, was 87,245 of which 17,129 were unique (Rint = 0.044 ); 15,244 were 'observed' with I > 2σ I . Data were processed using the CrysAlisPro-CCD and -RED (S1) programs. The structure was determined by the intrinsic phasing routines in the SHELXT program (S2) and refined by fullmatrix least-squares methods, on F 2 's, in SHELXL (S2). The non-hydrogen atoms were refined with anisotropic thermal parameters. The hydrogen atoms were included in idealised positions and their Uiso values were set to ride on the Ueq values of the parent carbon atoms. At the conclusion of the refinement, wR 2 = 0.070 and R 1 = 0.038 (2B) for all 17,129 reflections weighted w = [σ 2 (F o 2 ) + (0.0290 P) 2 + 16.8113 P] -1 with P = (F o 2 + 2F c 2 )/3; for the 'observed' data only, R 1 = 0.031.
In the final difference map, the highest peak (ca 1.6 eÅ -3 ) was near Au(2).
Scattering factors for neutral atoms were taken from reference (S5). Computer programs used in this analysis have been noted above, and were run through WinGX (S4) on a Dell Optiplex 780 PC at the University of East Anglia.
The crystal was a yellow block. From a sample under oil, one, ca 0.05 x 0.10 x 0.10 mm, was mounted on a small loop and fixed in the cold nitrogen stream on a Rigaku Oxford Diffraction Xcalibur diffractometer, equipped with Mo-Kα radiation, Sapphire detector and graphite monochromator. Intensity data were measured by thin-slice ω-scans. Total no. of reflections recorded, to θ max = 29.4, was 21,591 of which 9955 were unique (Rint = 0.032 ); 8411 were 'observed' with I > 2σ I .
Data were processed using the CrysAlisPro-CCD and -RED (S1) programs. The structure was determined by the intrinsic phasing routines in the SHELXT program (S2) and refined by fullmatrix least-squares methods, on F 2 's, in SHELXL (S2). There is solvent, CH 2 Cl 2 , included in the lattice, disordered over two orientations. The non-hydrogen atoms were refined with anisotropic thermal parameters. The hydrogen atoms were included in idealised positions and their Uiso values were set to ride on the Ueq values of the parent carbon atoms. At the conclusion of the refinement, wR 2 = 0.056 and R 1 = 0.039 (S2) for all 9955 reflections weighted w = [σ 2 (F o 2 ) + (0.0188 P) 2 ] -1 with P = (F o 2 + 2F c 2 )/3; for the 'observed' data only, R 1 = 0.029.
In the final difference map, the highest peak (ca 1.0 eÅ -3 ) was near Au(1).
Scattering factors for neutral atoms were taken from reference (S5). Computer programs used in this analysis have been noted above, and were run through WinGX (S4) on a Dell Optiplex 780 PC at the University of East Anglia. The crystal was a colourless block. From a sample under oil, one, ca 0.20 x 0.20 x 0.20 mm, was mounted on a small loop and fixed in the cold nitrogen stream on a Rigaku Oxford Diffraction Xcalibur diffractometer, equipped with Mo-Kα radiation, Sapphire-3 detector and graphite monochromator. Intensity data were measured by thin-slice ω-scans. Total no. of S17 reflections recorded, to θ max = 27.5, was 12,580 of which 6737 were unique (Rint = 0.030 ); 5677 were 'observed' with I > 2σ I . Data were processed using the CrysAlisPro-CCD and -RED (S1) programs. The structure was determined by the intrinsic phasing routines in the SHELXT program (S2) and refined by fullmatrix least-squares methods, on F 2 's, in SHELXL (S2). The t Bu group of C(17) was found to be disordered in two orientations with occupation ratio of 0.832 : 0.168. There are two difference peaks parallel to the Au(1)…Cu(1) vector, and very similar in distance apart; these were included as Au (2) and Cu(2) in the refinement process with an occupation factor which refined to 0.064; no further coordinated atoms/peaks were observed. The non-hydrogen atoms (except the minor components of the disordered t Bu group) were refined with anisotropic thermal parameters. Hydrogen atoms were included in idealised positions and their Uiso values were set to ride on the Ueq values of the parent carbon atoms. At the conclusion of the refinement, wR 2 = 0.080 and R 1 = 0.038 (2B) for all 6737 reflections weighted w = [σ 2 (F o 2 ) + (0.0385 P) 2 + 0.4868 P] -1 with P = (F o 2 + 2F c 2 )/3; for the 'observed' data only, R 1 = 0.030.
In the final difference map, the highest peak (ca 0.86 eÅ -3 ) was near Au(1).
Scattering factors for neutral atoms were taken from reference (S5). Computer programs used in this analysis have been noted above, and were run through WinGX (S4) on a Dell Optiplex 780 PC at the University of East Anglia.
Only for connectivity. [{(C^C)Au(C≡CC 6 H 4 OMe-4) 2 }{Cu(C≡NXyl)}] 5c Colourless block (0.1×0.1×0.05) grown by layering with petrol a solution of the solid in CD 2 Cl 2 . The symmetry space group of the crystal is P2 1 /n. A SHEL 0.8 999 instruction was used. EADP was used in some carbon atoms. DFIX was used for modelling the OMe substituents. Many Q peaks larger than 1 with no chemical meaning were found, what causes several A alerts in the checkcif.
Besides, the poor Thermal parameters of several atoms cause other A alerts in the checkcif.
Due to the poor quality and the unfruitful attempts of growing higher quality crystals, this structure is provided only for connectivity purpose. S18 Table S1. Selected crystal data and structure refinement details for:    showing (a) a general view (b) a side view that highlights the "in plane" disposition of the Cu(C≡NXyl) fragment.   Figure S16. UV-Vis Absorption Spectra in CH 2 Cl 2 5 × 10 -5 M of complexes 1 and 2 (i) 3a, 3b

S4. Theoretical Calculations
Calculations were carried out with the Gaussian 16 package1, using GaussView 6 to visualize the results. Overlap populations between molecular fragments were calculated using the GaussSum 3.0 software. S6 Three functionals were studied B3LYP, S7 CAM-B3LYP S8 and ωB97X-D S9 , being the range-separated and dispersion-corrected hybrid density functional ωB97X-D the one to better predict the emission energies. The basis set used for the metal atoms was the LanL2DZ effective core potential and 6-31G(d,p) for the ligand atoms. S10 No negative frequency was found in the vibrational frequency analysis of the final equilibrium geometries.
The effect of the solvent in the ground state calculations (DFT, TD-DFT) was taken into account using the polarized continuum model approach (PCM) S11 implemented in the Gaussian 16 software while the T1 state calculations were performed without any solvent. The emission energies were calculated as the difference between the optimized T1 state and the S0 state in the optimized T1 geometry (adiabatic electronic transition). S12